Given:
The car used 16 gallons to travel 304 miles.
Let x represent gallons of gasoline needed to travel 342 miles.
Using proportions:
[tex]\frac{16}{304}=\frac{x}{342}[/tex]solving for x:
[tex]\begin{gathered} 16\times342=304x \\ 5472=304x \\ \\ x=\frac{5472}{304}=18 \end{gathered}[/tex]ANSWER
18 gallons of gasoline needed to travel 342 miles